title: The role of an aromatic group in remote chiral induction during conjugate addition of alpha-sulfonylallylic carbanions to ethyl crotonate.
abstract: The impact of a remote aromatic nucleus on the stereochemical outcome of the conjugate addition of alpha-sulfonylallylic carbanions to an alpha,beta-unsaturated ester was investigated. alpha-Regioselectivity coupled with anti-diastereoselectivity is accompanied by a prominent preference for relative configuration 3 over 4. The 9-anthryl moiety has shown itself greatly superior over all other groups in this bias. A lithium ion-aromatic pi interaction has been postulated as decisive for the remote transmission of chirality.
authors.affiliation: Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Shlomo
authors.initials: S
authors.lastname: Levinger
authors.forename: Ranjeet
authors.initials: R
authors.lastname: Nair
authors.forename: Alfred
authors.initials: A
authors.lastname: Hassner